Global warming has mandated a multitude of domestic federal and state regulations and international treaties all designed to limit the harmful effects related to the combustion of fossil fuels. These regulations generally target CO2 emissions, which have been acknowledged by some as contributing to atmospheric greenhouse heating.
Over the past few decades different countries have experienced interruptions in the availability of fossil fuel supplies due to an external oil embargo and domestic natural disasters. In addition, countries face the lingering threat of direct energy terrorism targeted at our petroleum refineries and related infrastructure. Indirect threats also exist in the form of political/terrorist blackmail which may cut off access to any non-domestic source of oil supplies without warning. For example, the current rate of crude oil consumption in the United States is calculated to be approximately 12 million barrels per day. If an emergency forced the U.S. to become solely dependent on the United States Department of Energy Strategic Petroleum Reserve, (as of February 2008 the capacity was 698.6 million barrels) this national backup would be depleted in approximately 57 days. Obviously, such a scenario doesn't take into account the probability of fuel rationing nor the petroleum output of Canada and Mexico. It does, however, highlight the United States' acute vulnerability.
Finally, some studies suggest that within 10 to 15 years the worldwide supply of crude oil deposits may be reaching the point of peak production, known as the Hubbert Point, after which supplies will steadily diminish followed by an ever-increasing cost to the consumer. The rise of crude oil prices from early 2008 to September 2008 proved to be burdensome for businesses and consumers worldwide. These prices may be mere hints of what will unfold when real crude shortages begin.
Clearly, the issues described above suggest that continued dependency on fossil fuels is a tenuous course. As a consequence, a number of non-fossil fuel based alternative fuels are being evaluated and tested for transportation including ethanol, bio-diesel, electric, and hydrogen to name a few.
Some manufacturers are pursuing electric and hybrid-electric vehicle alternatives. However, it has been suggested that a major drawback with increasing the number of electric and hybrid-electric vehicles in use is the large quantities of batteries to power the electric motors and other electrical devices. These vehicles use batteries of one kind or another (i.e., lead acid, lithium-ion, etc.) to store an electrical charge. If improperly charged, batteries can be permanently damaged. Additionally, if left uncharged for long periods of time, the batteries can sulfate or become unusable. Moreover, battery storage is heavy, space consuming, offers maintenance challenges and offers limited life. Batteries used typically for vehicles of the state-of-art have an average effective life of 8 to 10 years and must be disposed of after their lifecycle, thereby creating a daunting environmental hazard. Studies reveal that 20 percent of car batteries are discarded in land fills.
Typical combustion engines are fueled by hydrocarbons. These combustion engines are generally used to power vehicles directly or are used to drive electric generators that provide power to electric drive motors. These engines have a standard efficiency of approximately 33 percent when fossil-fueled, and create pollutants such as carbon dioxide (CO2), carbon monoxide (CO), nitrous oxide and dioxide (NOx), and unburned hydrocarbons from combustion. Typically, aside from the estimated third of fuel energy converted to mechanical energy, another third is manifested into heat energy and the remaining third is expended into exhaust gas energy. By comparison, diesel engines are more efficient than gas engines, at approximately 40 percent. The addition of turbocharging and/or supercharging also increases efficiency. Fuel cell efficiency ranges from an estimated 50 to 60 percent.
Hydrogen as a combustible fuel source creates no carbon-based emissions. Although conventional piston-type internal combustion engines can be modified to accept hydrogen fuel, the drawbacks are hydrogen pre-ignition and high levels of NOx emissions. Pre-ignition problems arise from hydrogen's low ignition energy, wide flammability range, and short quenching distance. The elevated NOx emissions are a result of mixing hydrogen with atmospheric air, which consists of approximately 78 percent nitrogen. The typical cause of elevated NOx numbers is a high compression ratio which is commonly used in hydrogen-fueled internal combustion engines to increase horsepower. NOx production in the combustion chamber can also be attributed to variables such as the air/fuel ratio, engine speed, ignition timing, and the presence of thermal dilution.
Hydrogen engines can combust hydrogen which is drawn from pressurized storage tanks. These pressurized storage tanks are filled directly with hydrogen much like current vehicles are filled at a gas station. Fuel cell vehicles, also presently under prototype development and early market testing, call for similar fueling techniques. Hydrogen filling stations will be but a piece of a huge hydrogen infrastructure dedicated to hydrogen creation, shipping, storage and delivery. Such a hydrogen economy will necessitate a monumental public and private sector investment. Also critical are the dissemination of industry standards for fueling devices and safety regulations that include mandated training to ensure proper handling of this unique fuel.
Hydrogen as a combustible fuel source may be stored in liquid form in a super-cooled liquid state or in the lattice of a metal hydride. The cryogenic system required to maintain the liquefaction is minus 253 degrees Celsius for hydrogen. The benefit of this approach is an estimated 10 fold increase in energy density (over compressed gaseous form) for both the fuel and the oxidizer. The liquefaction of hydrogen improves the energy density to within 20 percent of that of gasoline. The drawback of this method is the higher energy required 24/7 to maintain the refrigeration system versus the energy necessary to compress the gases in the low pressure (0 to 1,500 psi) and high pressure (1,500 to 10,000 plus psi) tanks. While compressing the gas draws energy during filling the tanks and compression can be stabilized without additional energy, refrigeration requires a continuous energy output to preserve the temperature sensitive cryogenic state. In the event of a refrigeration system failure, the liquids innately revert back to a gaseous state which would require tanks of sufficient size to contain the gases. If the tank size is inadequate, then the rapid expansion from a liquid to gaseous state will likely result in a tank rupture and possibly an explosion.
The option of storing the hydrogen as a solid in a metal hydride compound, nano-suspension or other solid form has drawbacks as well. The practicality of storing oxygen in this form, as it applies to the present invention, is unknown. In order to access the hydrogen stored as a solid, heat energy is required to stimulate the release of the hydrogen from its metal hydride compound, nano-suspension, or other solid state. Furthermore, as the hydrogen harvest nears depletion, it becomes more difficult to collect. The environmental impact of metal hydride disposal may be addressed by removing the hydride from the metal container and disposing of each separately. The storage of hydrogen in nano-tubes is, at this point, an unknown technology in terms of reliability, risks human and environmental poisoning, and after use, disposal pollution particularly to underground water tables.
One ideal solution to the shortage in fossil fuel supplies includes a domestic energy source that has zero harmful emissions. Because of the vast demand for energy, such an energy source must be available in sufficient volume to meet the needs of the socio-economic marketplace. It should be derived from a source that is renewable in the most environmentally responsible fashion. That is, if possible, the cycle from production to disposal will be pollution free and non-toxic. Perhaps most importantly, as certain countries increase their development of solar and wind power flowing through an improved energy grid, these advances will actually reduce the consumer's cost of this new energy. As the present invention indicates, a strong contender for this energy source may be common water. It is the most plentiful substance on earth and is inherently non-toxic.